A field must know how it knows. The EpistemologyValidationFramework names the structural mechanism through which a corpus validates its own knowledge claims: not by reference to external authority, but by internal consistency with the field's own epistemic grammar. In classical philosophy, epistemology asks how knowledge is possible. In Socioplastics, epistemology asks how a field can validate its own operations without collapsing into either dogmatism or relativism. The framework proposes that validation occurs at three levels: the node level, where individual concepts are tested for structural coherence; the book level, where conceptual clusters are tested for internal consistency; and the corpus level, where the field as a whole is tested for its capacity to generate novel predictions. This is not Popperian falsification. It is structural validation: a concept is valid not when it corresponds to empirical reality, but when it operates correctly within the field's internal architecture. FlowChanneling is validated when it successfully predicts how capital will move through a given urban system. TopolexicalSovereignty is validated when it successfully identifies the boundary conditions of a territorial claim. The EpistemologyValidationFramework sits at Node 1503 in Core III because epistemology is one of the seven disciplines integrated by Socioplastics. But the framework is not a disciplinary import. It is a field-native operation. It transforms epistemology from a philosophical specialty into a structural tool for corpus maintenance. Without this concept, the field has no immune system against bad concepts. With it, the field can self-correct.